Unintended allusions are part of the Nabokovian illusion.
J.A.:Think this is especially true of a book like Pale Fire. Bootle writes his point very amusingly.
My ongoing working hypothesis when meeting an unusual turn of phrase in VN's corpus delectable: these words have been chosen with an almost inhuman devotion, precision and purpose...
Even in the context of weather vanes, the predication "stiff" is meaningful. Weather vanes indicate the wind direction, but should not be over-sensitive to tiny transient gusts.
J.A.: I like this meaning of "stiff weather vane" best of the crop we've had, but I think I would disagree that one should always doubt oneself when coming up against what seems a questionable wording. For instance in Ada, late in Part one, at a pool party Van describes Ada as smelling of "axilary tufts" meaning underarm odor, which is not much more economical (this description does also throw in hairiness, whereas the more common does not, but it seems to that N. lost more than he gained expressively.